package com.hmdp.utils;

import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Component;

import javax.annotation.Resource;
import java.time.LocalDateTime;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;

@Component
public class RedisIdWorker {
    private static final long BEGIN_TIMESTAMP = 1640995200L;
    //时间戳向前位运算位数
    private static final int COUNT_BITS = 32;
    @Resource
    private StringRedisTemplate stringRedisTemplate;
    public long nextId(String keyPrefix) {
        // 1.生成时间戳
        LocalDateTime now = LocalDateTime.now();
        long nowSecond = now.toEpochSecond(ZoneOffset.UTC);
        long timestamp = nowSecond - BEGIN_TIMESTAMP;
        //2.生成序列号
        //获取当前日期精确到天
        String date=now.format(DateTimeFormatter.ofPattern("yyyy:MM:dd"));
        //通过添加每天日期来防止键值不足
        //自增长
        long count=stringRedisTemplate.opsForValue().increment("icr:" + keyPrefix+":"+date);

        //3.拼接并返回
        return timestamp << COUNT_BITS | count;
    }

    public static void main(String[] args) {
        LocalDateTime localDateTime=LocalDateTime.of(2022, 1, 1, 0, 0, 0);
        long time =localDateTime.toEpochSecond(ZoneOffset.UTC);
        System.out.println(time);
    }
}
